Dynamoelectric devices such as generators are widely used in aircraft to generate electrical power required to operate the many systems on board the aircraft. Such dynamoelectric devices are naturally subjected to extreme environmental conditions. For example, in high performance aircraft, the generator is subject to ambient pressure altitudes from -1,000 to 80,000 feet, and to ambient temperatures from -65.degree. to 700.degree. F. In order to maintain proper conditions within such generators, it is frequently necessary to provide a sealed generator housing allowing for retention of a gas provided in the generator (i.e., nitrogen may be provided to keep the moisture out of the generator and to provide a positive pressure to enhance oil scavenge). Such a sealed housing is also necessary in order to allow for proper circulation of coolant and lubricant without leakage.
The generator housing encloses both a stator and rotor, and the rotor may include an electromagnetic core and winding assembly provided between two stub shafts or "endshafts". In a high speed, 24,000 R.P.M. generator arrangement a containment sleeve surrounding the electromagnetic core and winding assembly is usually secured at each end thereof to the respective endshafts by welding. The cylindrical metallic sleeve provides mechanical support for the core wedges and hermetic sealing of the core space. The absence of a shaft passing through the core assembly allows for the Passage of cooling oil inside the rotor. The sleeve also transmits torque between the endshafts, which are driven at 24,000 R P M. by a gear mounted on one of the endshafts.
However, the practice of welding the endshafts to the sleeve has proved problematic. The welding techniques necessary to meet the physical demands of the generator applications are relatively complex. Furthermore, welding also introduces distortion of critical match machined components in the assembly, which renders repair of the assembly impracticable.
It is therefore apparent that there exists a need in the art for a rotor assembly in which a cylindrical containment sleeve may be simple and effectively secured to a pair of endshafts, while retaining the torque-transmitting abilities of known arrangements.